About

Aerosol particles in the atmosphere have an important influence on the Earth's radiative balance by directly reflecting sunlight back into space, as well as absorbing some sunlight and converting it into heat. Aerosols also have an impact on climate by acting as cloud condensation nuclei, which alters cloud properties and their radiative effects. Aerosol particles at surface level impact human health, and are associated with disruption to transport (desert dust storms and volcanic eruptions) and can reduce the solar irradiance available for solar power plants.

Objective

The driving objective of the CCI Aerosol project is to provide independently validated, high quality algorithms for processing long-term records of global aerosol properties from European satellite instruments.

The current Aerosol project, running May 2025 to December 2026, focuses on completing algorithm improvements for the dual view sensor line, in particular the Sentinel-3 SLSTR instrument together with one user case study (data assimilation for climate services) and community support (AEROSAT coordination support). Another user case study is linked in the ESA Cliamte-Space cross-ECV project SATACI (feasibility study for an aerosol and cloud cooling offset climate indicator).

The processing of long-term records (6-monthly extensions and complete reprocessing every 2-3 years) has been transferred to the Copernicus Climate Change Service since 2018 within the contracts C3S_312a_Lot5 (October 2016 – September 2018), C3S_312b_Lot2 (October 2018 – June 2021), C3S2_312a_Lot2 (November 2021 - April 2024) and C3S2_313a (June 2025 - December 2027).

In response to the requirements of the Global Climate Observing System (GCOS) and the AEROCOM international modelling community, the three former phases of the Aerosol have focused on:

• Improving and assessing algorithms for total aerosol optical depth
• Improving and assessing algorithms for fine / coarse mode aerosol optical depth and for dust optical depth
• Improving and assessing algorithms for stratospheric extinction profiles
• Testing algorithms for further aerosol quantitates (effective layer height, single scattering albedo / absorbing aerosol optical depth)
• Working with the AEROCOM community as a primary user and conducting ten dedicated user case studies on the applicability of those data sets, their strengths and weaknesses.

Aerosol Phase 1 ran July 2010 to February 2014; Phase 2 ran May 2014 to October 2019. Aerosol_cci+ Phase 1 extended from March 2019 to July 2022.